1. Technical Field
The present invention relates generally to an antenna radiating device, and more particularly, to a dual flared slotline antenna radiating device incorporating a wide bandwidth in an arrayable configuration.
2. Discussion
Antenna radiating devices, particularly driven at microwave frequencies, are required in certain systems such as radar and electronic warfare systems. Due to a variety of obvious as well as complicated factors, it is highly desirable to provide all of these radar and electronic warfare functions on a single, low-profile system. Because of this, many constraints on an antenna radiating device incorporated in the low-profile system, such as wide bandwidth, small size, polarization diversity and conformality, are required in order to realize a system which meets all of the requirements of each different function. Furthermore, it is necessary that low radar cross section characteristics are also maintained. The success of such systems have heretofore been limited in attempting to develop a low-profile system which adequately meets all these characteristics at a high level of effectiveness.
Presently, the most commonly used antenna element in these multifunctional systems is the so-called cross flared notch antenna, known in the art. See for example, Povinelli, Desion and Performance of Wideband Dual Polarized Stripline Notch Arrays, 1988 IEEE AP-S International Symposium, Volume I, "Antennas and Propagation," June 6-10, 1988. However, cross flared, notched antennas have the disadvantage of ineffective conformality. In other words, the depth dimension of the antenna is significant enough to severely limit its ability to conform to desirable structures. Further, reducing the depth dimension of the antenna will result in limiting the impedance match to free space at the low frequency end of the operating band.
A second design attempting to satisfy the characteristics of the above-described functions is the dual flared slotline antenna. See for example, Povinelli, Further Characterization of a Wideband Dual Polarized Microstrip Flared Slot Antenna, 1988 IEEE AP-5 International Symposium Volume II, "Antennas and Propagation," June 6-10, 1988. Although the dual flared slotline antenna is low-profile and arrayable, its impedance bandwidth is limited by its conventional transition to slotline. In addition, it does not satisfy many size constraints and has four feed points per antenna element which necessitates the use of two driver networks.
What is needed then is an arrayable antenna which includes the characteristics of wide bandwidth, small size, polarization diversity and conformality in order to provide the necessary requirements for multifunctional systems, and further, has a reduction in the number of feed points per antenna element required over the prior art systems. It is therefore an objective of the present invention to provide such an antenna.